The present invention relates to a sealing ring which consists of an elastic material, preferably rubber, for sealing the space between two sealing surfaces which are axially displacable to a substantially concentric position in relation to each other, preferably for sealing the space between a socket and a spigot of a pipe joint, and a method of manufacturing such a sealing ring.
Sealing rings for sealing the annular space between a socket and a spigot in a pipe joint are of two main types, rolling rings and sliding rings. In a conventional sliding ring joint the sliding action takes place between the sealing ring and at least one of the sealing surfaces when the sealing surfaces are axially displaced in relation to each other. In order to reduce the friction forces between the ring and the sealing surface at which the sliding takes place it is necessary to apply a lubricant on the sealing ring. However, sealing rings of the above type have certain drawbacks. Thus, it is a time consuming and unpleasant work to apply the lubricant and there is also the risk of pollution of the surfaces provided with lubricant after the positioning of the sealing ring in the starting position for the axial displacement of the sealing surfaces to the concentric position.